Ext.data.Store does:

Code:
 add: function(arg) {

        
        if (Ext.isArray(arg)) {
            records = arg;
        } else {
            records = arguments;  // BOOOOOOOOH
        }

Should normalize it to real array. Any 'instanceof Array' or Ext.isArray checks on the Records param fails now... Docs would also be lying right now since they state it should be an Array of records.